Patterns of substance use among adolescents in California schools

There is a dearth of information regarding national rates of adolescent substance use. However, there is data to support that there are significant state-level variations in patterns of adolescent substance use. The current study uses the California Healthy Kids Survey to identify latent classes/clusters of lifetime and frequency (number of days) of recent (past month) alcohol, tobacco, and marijuana use (N=436,584). Demographic characteristics (age, gender, race/ethnicity) were included as predictors of latent class membership. Analyses revealed four latent classes of substance use which included non-users (63%), alcohol experimenters (some recent alcohol use; 22.1%), mild poly-substance users (lifetime use of all substances with less than three days of recent use; 7.9%), and frequent poly-substance users (used all substances three or more times in the past month; 7%). Older age increased the likelihood of being in any use class compared to non-use. Females were more likely to be mild poly-substance users than males (OR=1.35, 95% CI=1.24-1.47) but less likely to be frequent poly-substance users (OR=.60, CI=.56-.65). Racial/ethnic differences indicated that African Americans and Hispanic adolescents were twice as likely to be alcohol experimenters then their white counterparts but less likely to be frequent poly-substance users. This study makes two important contributions. First, few studies have explored both lifetime and frequency of recent substance use simultaneously. Second, the use of latent class analysis provides greater detail regarding substance use behaviors among California adolescents. This information can be used to identify specific substance use patterns most salient for targeting in school-based prevention efforts.